Quick
justin's gas tank is 1/6 full. after he buys 7 gallons of gas, it is 1/2 full. how many gallons can justin's tank hold?

21 gallons

Step-by-step explanation:

The tank is half full after the 7 gallons goes into it.  It started with 1/6 of a tank.  1/2 - 1/6 = 1/3.  That means that it took 7 gallons to fill that 1/3.  We can use proportions now to solve this:

where x is the number of gallons when the tank is full (1).  Cross multiply to get:

so

x = 21 gallons

part a: 1.08

part b: 27.59

-3.5 degrees per hour

step-by-step explanation:

find the unit rate:

-12   1/4 degrees           12.25 degrees

= - = -3.5 degrees per hour

      3   1/2 hours               3.5 hours